Field of the Invention
The present invention relates to a removable ground anchor body using a spring, and more particularly, to a removable ground anchor body using a spring that is coupled to an end portion of a fixing portion of a pre-stressed concrete (PC) strand wire such that a perfect coupling state is kept even by movement or external impact in the field and at the same time a tensile material such as a PC strand wire can be easily separated and removed even by man power.
Description of the Related Art
In general, a slope reinforcement structure coupled with a PC strand wire is to form holes in the ground by drilling, insert a tensile material with excellent tensile strength into the drilled holes with an internal fixing agent and inner member, thereafter, firmly fix it by injecting with a grouting material such as concrete, and thereafter, apply a load to a free end of the tensile material, fix it with an external fixing material and ensure a strong fixation force to safely support structures such as earth retaining walls. Such a slope reinforcement structure is widely used in a soil retailing construction for preventing the collapse of the surrounding ground at the time of excavation for underground structures of the building construction and civil engineering, a construction for suppressing the sediment loss of the soft ground incision surface.
As the tensile material used in the slope reinforcement structure, a tensile material made by twisting a plurality of strands of deformed bars or steel wires is used. Since the tensile material has outstanding strength, if it is left in the ground it becomes a ground obstacle, and there is a risk of causing a problem such as the ground compensations in future development of adjacent land.
To solve this problem, a removable internal fixing material for ground anchor for easily removing the tensile material embedded in the ground after the construction has been known.
Such a conventional anchoring body has a configuration in which an inclined surface is formed inside a cylindrical body, a wedge divided into approximately three pieces is provided on the inner surface of the inclined surface, the tensile material seats on the central portion of the wedge, and an elastic spring for pressing the wedge forward is provided at the rear end of the wedge to press the wedge to prevent detachment and separation of the tensile material.
However, according to the structure of the conventional anchoring body, in order to remove the tensile material, the tensile material is pressed to retract the wedge provided on the inside of the cylindrical body, and at the same time, the tensile material can be removed in the state of expanding the central portion. However, even when retracting the wedge, the expansion is not correctly performed, and even when the wedge is moved back to perform the expansion, since the spring provided in its rear end continuously presses the wedge, there is still a problem in that a burden may occur upon removal of the tensile material and the separation may not be performed correctly.
In the conventional removable internal fixing agent, there was a problem in that it was not possible to easily remove the tensile material in the future, when an impact is applied to the internal fixing material of the PC strand wire in the course of transporting the PC strand wire manufactured in the factory to a construction site or in the course of handling at the time of construction work.
Furthermore, since it is almost impossible to reassemble the anchor body in which the coupled state is separated due to the external impact in the field, a major obstacle was caused in the progression of construction.
There is a technique of Korean Patent Registration No. 10-0963565 in which these problems are improved, although such a technique presses the wedge by elasticity of the upper spring to continually maintain the bound state with the tensile material and allows the re-coupling, while suppressing the wedge from being separated due to the external impact during transportation or handling process, there were drawbacks in which it was not possible to basically prevent the separation of the tensile material due to the spring contraction caused by external impact energy from the outside, and it was not possible to remove the tensile material by the man power after the installation of the slope.